Ok, update. I have read that for some reason..Ata 100 only supports up to 137GB, it is a hardware limitation. Dont know why they would make a 160gb ATA 100 HD then...?
Its a limitation for Windows. If you have service pak 1 atleast you should be able to see the remaining space. Go to control panel > Administrative tools > then Computer management > then click storage and then disk management. It will show the partitions already setup and hopefully you will be able to see the remaining hard disk space that is unpartitioned. Just format and then your good